Most modem automotive vehicles are powered by an internal combustion engine that is connected with a source of fuel, e.g., gasoline, diesel, natural gas, alcohol, hydrogen, etc. The fuel is stored on-board the vehicle and supplied to the engine in a precisely controlled manner.
According to a conventional fuel system, as shown in FIG. 11, gasoline is stored in a tank on-board a vehicle. The gasoline is withdrawn from the tank by a pump and fed through a filter to fuel injectors, which deliver the gasoline to combustion cylinders in the engine. The fuel injectors are mounted on a fuel rail to which fuel is supplied by the pump. The pressure at which the fuel is supplied to the fuel rail must be metered to ensure the proper operation of the fuel injectors. Metering is carried out using pressure regulators which control the pressure of the fuel in the system at all levels of engine speed.
Known pressure regulators, as shown in FIG. 12, employ a spring biased valve seat with a longitudinal flow passage. A detailed view of a known valve seat is shown in FIG. 13. The valve seat is biased to a closed position to prevent the flow of fuel through the pressure regulator at low fuel pressures. As fuel pressure builds in the system, the pressure against the valve seat overcomes the biasing force of the spring, allowing fuel to flow through the valve seat, thereby controlling the fuel pressure in the system.
Fuel flow rate, measured in liters per hour, through known pressure regulators tends to be low at high engine speed, measured in revolutions per minute, as large quantities of fuel are consumed in the combustion process. At low engine speeds, less fuel is consumed in combustion and flow rates through the pressure regulators are high. These high fuel flow rates through known pressure regulator valve seats produce unacceptably high noise and pressure levels. A valve seat is needed that maintains flow-related noise and pressure within acceptable levels, even at high fuel flow rates.